The ouster of the number two administrator at the National Endowment for the Arts has aroused some concern among participants in the ongoing battle over the agency's policies.

Neither NEA Chairman John Frohnmayer nor Senior Deputy Chairman Alvin S. Felzenberg would discuss the reasons for Felzenberg's future departure yesterday, but sources inside and outside the NEA said there has been an open managerial and philosophical rift between the two since the deputy arrived at the agency early this year. Although no NEA or White House sources would say publicly that Felzenberg had been fired, they verified reports that he will leave due to clashes with Frohnmayer.

Felzenberg had recommended modifications to NEA grant policies to answer some congressional concerns, said a White House source. He was seen within the endowment as espousing a more cautious approach on funding potentially controversial art than that taken by Frohnmayer in recent months, according to endowment sources. Felzenberg, who ran the New Jersey arts commission for Gov. Thomas Kean before coming to Washington, had been selected for the newly created NEA job by the White House, reportedly against Frohnmayer's wishes.

Felzenberg, who is expected to find a new job in the Bush administration, declined to discuss his situation. "I do not comment on personnel decisions or matters in the agency, including those that affect me," he said yesterday. "That's all I'm going to say. I'm at the endowment now, I will be at the endowment tomorrow. I have not been fired or resigned."

Frohnmayer would not comment beyond an official statement released Friday by his press office that said, "The job did not work out to either party's satisfaction. Dr. Felzenberg has indicated he plans to seek another opportunity to serve the president."

A White House official said yesterday, "I think Frohnmayer was looking for a number two who was an administrator, who was going to administer the agency, and he just didn't feel that he was doing it adequately. But maybe Felzenberg thinks it was more philosophical."

As news of the move spread, people skeptical of the embattled agency said it may increase criticism of the agency, particularly within the Bush administration.

Rep. Thomas Coleman (R-Mo.), who sits on the subcommittee currently considering the NEA's reauthorization and has proposed a radical restructuring of the agency, said of Felzenberg's departure, "Without talking about that specific case, I think it may reflect a below-the-surface difference within the administration."

A government source closely involved with the NEA said: "John Frohnmayer's support in the White House is of special interest ... but how deep that support goes is being questioned. Frohnmayer seems to have the confidence of the president, but support within the ranks of the White House staff is uncertain."

A senior administration official said yesterday that White House Chief of Staff John H. Sununu had asked for "an explanation" of Felzenberg's situation.

Chase Untermeyer, White House personnel director, said that Felzenberg had "not been fired. He has not left. There is no vacancy yet" in his post, although "his situation at NEA is very, very difficult." Untermeyer praised Felzenberg's ability to "understand the relationship between politics and the arts."

Staff writer Ann Devroy contributed to this report.